With the increased use of mobile electronic devices, including, but not limited to, smart phones, laptop computers, and tablet computers, demand for portable power systems has increased. A popular solution is the use of rechargeable batteries, such as lithium-ion or lithium polymer batteries. For many mobile electronic devices, rechargeable batteries, even when replaceable by a user, are left in the device during use and charging of the battery.
Despite advances in battery designs leading to reduced size and increased capacity, rechargeable batteries impose a number of restrictions on users. First, battery capacity is often only enough to provide for a few hours of active use for many mobile electronic devices. For example, many laptop computers include batteries sufficient for around 5 hours of use, and many smartphones include batteries sufficient for approximately a full day's use. Second, rechargeable batteries must be recharged, which generally requires multiple hours to fully recharge a battery. The combined need to have an appropriate charging device on hand, access to an electrical outlet for the charging device, and adequate time to leave the mobile device attached to the charger for charging, imposes a significant inconvenience on users. Although some devices feature user-replaceable rechargeable batteries, and in theory a user might have an extra charged battery on hand, in practice users rarely find this to be a convenient solution.
Fuel cell technologies have advanced, in terms of size, reliability, and cost, to where fuel cell based power systems can replace or supplement conventional rechargeable battery based solutions. One advantage of fuel cell systems is increased energy density over rechargeable battery technologies. For example, a hydrogen fuel based fuel cell system, including the weight of hydrogen fuel, a storage canister for the fuel, a fuel cell stack, and a “balance of plant” for a fuel cell subsystem, can offer approximately a 1-fold increase in energy density over a lithium-based battery solution. As a result, in comparison to battery-based counterparts, fuel cell based power allows for lighter designs and/or greater run time.
However, fuel cell based power imposes a significant requirement: ensuring there is adequate fuel on hand. The fuel is volatile, and often compressed at a significant pressure, meaning that appropriate storage must be provided for the fuel. For example, the use of cartridges for storing compressed hydrogen is known in the art, and provides a safe and reliable mechanism for supplying fuel to fuel cell powered devices. However, a convenient mechanism for controlled distribution and reuse of such cartridges is required in order to achieve successful commercial application of fuel cell power technologies.